Photoshop: Allow snapshots to be saved in the .PSD file

Often times I have three or four snapshots running with alts of the design I'm working on, and I may want to revisit them later. I'd love to be able to easily bring them back up without manually needing to save each one as a .psd. Can't we have a way to preserve them in the .psd file?

Unfortunately you cannot save snapshots. However you could make a dupe layer with each effect and mask it. Using snapshots and the history brush is a fast way to work, but not adjustable. In a pre-press workflow the work-around would be to make a dupe layer and name the layer with the current date; make adjustments and save as psd. This gives you the ability to work backwards if need be. Each time you open the file make a dupe layer with new date.

I work with Photoshop for a long time now and I think you can and should make a new feature in History. We can make Snapshots (Steps we made) but when we close the document, that is lost.
It would be VERY NICE and 'kewl' if it could be save that steps in .psd.